Recently, user interfaces using audio have been spreading. The user interface using audio are used in, for example, a mobile phone (a device called a smartphone or the like) when making a telephone call or searching for information.
However, if it is used under an environment having many noises, the audio generated by a user cannot be correctly analyzed, and processing can be wrongly performed. Thus, Patent Document 1 proposes that desired audio is extracted by reducing influence of a noise.